database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-11-16 15:02:33 +03:00
Code Activity

Reimplement free-space-map management as per recent discussions.

Browse Source 
Adjustable threshold is gone in favor of keeping track of total requested
page storage and doling out proportional fractions to each relation
(with a minimum amount per relation, and some quantization of the results
to avoid thrashing with small changes in page counts).  Provide special-
case code for indexes so as not to waste space storing useless page
free space counts.  Restructure internal data storage to be a flat array
instead of list-of-chunks; this may cost a little more work in data
copying when reorganizing, but allows binary search to be used during
lookup_fsm_page_entry().
This commit is contained in:
Tom Lane
2003-03-04 21:51:22 +00:00
parent a455c94257
commit 391eb5e5b6
10 changed files with 1165 additions and 741 deletions
Download Patch File Download Diff File Expand all files Collapse all files

9
src/backend/access/nbtree/nbtpage.c
View File

@@ -9,7 +9,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtpage.c,v 1.63 2003/02/23 23:20:52 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtpage.c,v 1.64 2003/03/04 21:51:20 tgl Exp $
*
* NOTES
* Postgres btree pages look like ordinary relation pages. The opaque
@@ -401,15 +401,10 @@ _bt_getbuf(Relation rel, BlockNumber blkno, int access)
* that the page is still free. (For example, an already-free page
* could have been re-used between the time the last VACUUM scanned
* it and the time the VACUUM made its FSM updates.)
*
* The request size should be more than half of what btvacuumcleanup
* logs as the per-page free space. We use BLCKSZ/2 and BLCKSZ-1
* to try to get some use out of FSM's space management algorithm.
* XXX this needs some more thought...
*/
for (;;)
{
blkno = GetPageWithFreeSpace(&rel->rd_node, BLCKSZ/2);
blkno = GetFreeIndexPage(&rel->rd_node);
if (blkno == InvalidBlockNumber)
break;
buf = ReadBuffer(rel, blkno);